def f(S, nums, depth):
    if depth != len(nums) :
        if f(S-nums[depth],nums,depth+1) :
            return True
        if f(S+nums[depth],nums,depth+1) :
            return True 
               
    return S==0 and depth == len(nums)
   
    
def main():
    D_INPUT = True
    
    if D_INPUT:
        numbresInput = raw_input().split(" ");
    else:
        numbresInput = "1 1 0 1".split(" ");
     
    nums = []
    for num in numbresInput :
        nums.append(int(num))
    

    S = nums[0]
    for i in xrange(1,len(nums)) :
        if f(S-nums[i],nums[1:i]+nums[1+i:],0) :
            print "YES"
            return
            
    print "NO"
        
                  
main()